I'm getting such good feedback on my other thread for my newly acquired '43 10EE that I'm going to throw out another question.
Every picture I can recall seeing of round dial headstock ends shows a drive belt idler on the left side (rear of lathe). Mine has an idler on the right, like some square dials. However, it ain't quite right -- the T-slot bracket doesn't have enough travel to allow the idler to adequately contact the belts:
In the picture the idler is moved as far left (rearward) as possible, and then some, with part of the T-bolt hanging out of the T slot. Perhaps the original idler wheel was larger in diameter? If so it must have been huge.
To the left (rear) there are two tapped holes where the T-slot bracket would presumably go for a rear mounted idler (barely visible in photo). I could just make a T-slot bracket to attach there and relocate the idler. I am curious as to the original configuration, however.
First my experience is with square dials, so there is the possibility that the round dial differs.
There should be two idlers - one on each side. The one you have should also have an angled bracket that rides in the T slot and positions the idler up higher and about and inch more towards the belt.
If you do a search you will find some pictures and drawings - someone here kindly measured theirs for me a while back as I was missing that part.
I also have an original EE idler mounting block for a round dial that I bought thinking they were the same as the square dial (they are not). Its sitting around till someone needs one.
First my experience is with square dials, so there is the possibility that the round dial differs.
There should be two idlers - one on each side. The one you have should also have an angled bracket that rides in the T slot and positions the idler up higher and about and inch more towards the belt.
If you do a search you will find some pictures and drawings - someone here kindly measured theirs for me a while back as I was missing that part.
I also have an original EE idler mounting block for a round dial that I bought thinking they were the same as the square dial (they are not). Its sitting around till someone needs one.
Paul
Found it, thanks ("idler pulley block dimensions"). Mystery solved, at least partially. Now that I'm paying attention I see both idlers in the MG picture at http://www.lathes.co.uk/monarch/img5.gif. I'm missing the left hand idler and it must have been gone far a long time because there are no traces in the grime that also fills the threaded holes.
But that leads me to another puzzlement. My one idler is just like the one in the PaulM thread "Idler Pulley Block FS": http://farm3.static.flickr.com/2429/...c6b4a877_m.jpg. My idler is correctly aligned with the belts yet like the one in that picture is bolted up tight to the block with the T-slot. I don't see how an angled bracket could be used without shifting the idler out of alignment. From the pictures in the other PaulM thread it looks pretty beefy. Perhaps there was another style of angled bracket for the MG units, or a spacer between the bracket and the T-slot block.
Steve, there's an apples and oranges problem here. The idler setups on round and square dial machines are different. Although the lathes are somewhat similar there are a great number of differences between them. There is no angled arm on the round dial right hand idler.
The lathe pictured in your lathes.co.uk link is the later design, the square dial.
The link below has a PDF manual for a 1942 round dial. It should help you with your lathe, there are many excellent photographs and drawings which show virtually every part of the lathe. Hope you have broadband, the file is nearly 52 MB. You won't regret having it.
Top center of page 14 shows the idler parts. IIRC they're the same for both sides.
On the UK lathe site there is a picture of a round dial with the idler on the other (left) side (and it only shows one pulley) http://www.lathes.co.uk/monarch/page5.html
Of course the round dial idler mounting block has the hole through it for the speed control (which is not shown in this picture), so it may be worth adding a second idler (as shown in the square dial pics). Certainly should not cause any problems. Purely from the pictures the left side idler appears to have sufficient travel to tension the belts and the right one just keeps you from having a long unsupported length that can vibrate (I'm speculating as my square dial was originally missing the right idler and the belts on that side did rub on things)
Dave - I wound up not making the angled support arm as I was able to get one on ebay (including a second original idler as well as a spare idler assembly for the flat belt) it was a good deal and I have not seen one since.
My 1943 round-dial just has one idler, on the left side, just like Figure E in the 1942 manual. But then, mine is a flat belt drive and so is the one in the manual. It's interesting that the idler for flat belt and V-belt seems to be the same.
Its interesting to see the differences in these machines.
Cal on your round dial you state your idler block is on the left (rear) side. Does it have a round hole through it (which would allow the speed control shaft to pass through if mounted on the right)?
The one I have has the hole and it was confirmed to have come off a round dial. From the pictorial evidence it looks like they did not put idlers on that (right) side - but from Steve's picture (and my part as well) it does appear they also mounted (some) idlers on the right. On square dial machines they clearly went with two.
Mine does not have a horizontal through hole and it's too small to be bored for one. It measures 3-1/2" wide by 2-1/4" tall by 1-1/4" deep. Between the two vertical mounting bolt holes and the horizontal T-slot there's no room for a through hole for the shaft (which is about 7/8" OD). The only way that I can see to mount one on the right side would be to replace the inboard pillow block for the back-gear/speed control shaft.
Its interesting to see the differences in these machines.
Cal on your round dial you state your idler block is on the left (rear) side. Does it have a round hole through it (which would allow the speed control shaft to pass through if mounted on the right)?
The one I have has the hole and it was confirmed to have come off a round dial. From the pictorial evidence it looks like they did not put idlers on that (right) side - but from Steve's picture (and my part as well) it does appear they also mounted (some) idlers on the right. On square dial machines they clearly went with two.
Paul
My right hand idler block has the hole through it. I have received my unique-to-my-serial-number manual from Monarch, it has a picture of the headstock end with -- you guessed it -- only one idler on the left side.
Note my right hand idler block can't be bolted on the left hand side -- both the spacing between the bolt holes and the lateral position along the long axis of the lathe are different than for the right side.
What's odd about my right side idler is that it doesn't quite reach the belt, and it doesn't look like the angled bracket (per the pictures and drawings from your earlier threads) would help. This picture better illustrates the problem:
Here the head of the T-bolt is hanging out of the end of the T-slot as far as it can without falling out completely (i.e. grabbing the T-slot on only one half of the square head). If I keep the T-bolt head entirely within the T-slot the idler doesn't touch the belt at all. The angled bracket widget would need a spacer fully as thick as the idler roller. Doesn't look original to me.
The only thing I can think of is that the block is designed to work with the 4000 RPM pulley set. But you have a 2500 RPM tach? Maybe someone changed out the pulleys and the tach to get better low end torque, but didn't bother to change the idler. It doesn't make sense...
I can think of two solutions: Make a new block for the left side (I can make a sketch of mine if you like). Or make a new T-bolt for the idler as mounted. I'm picturing a bar of metal with a shaft for the idler on one end and a bolt on the other. You would use a nut and washer with the bolt to lock the bar in place. Does that make sense?
The spare round dial idler mounting block I have looks to match the picture of Steve's (right side, shaft running through it). If the materials are on hand and the equipment is available I'd just make a block for the left side -or check what Rick has.
This may sound too simple, but have you checked that the belts are the right size (haven't stretched) or been swapped for some slightly larger ones for some reason?
I've had machines where the belts seem too slack and when I check someone has installed a larger one as it is easer to get on the pulleys...
The only thing I can think of is that the block is designed to work with the 4000 RPM pulley set. But you have a 2500 RPM tach? Maybe someone changed out the pulleys and the tach to get better low end torque, but didn't bother to change the idler. It doesn't make sense...
I can think of two solutions: Make a new block for the left side (I can make a sketch of mine if you like). Or make a new T-bolt for the idler as mounted. I'm picturing a bar of metal with a shaft for the idler on one end and a bolt on the other. You would use a nut and washer with the bolt to lock the bar in place. Does that make sense?
Cal
Yes, a 2500 rpm tach. Good thought, I could make an extended T-nut, several inches long with a permanently mounted stud shaft offset to one end. That would be the simplest fix.
Originally Posted by form_change
This may sound too simple, but have you checked that the belts are the right size (haven't stretched) or been swapped for some slightly larger ones for some reason?
I've had machines where the belts seem too slack and when I check someone has installed a larger one as it is easer to get on the pulleys...
Michael
That's a good question. I have two new A85 belts, haven't put them on yet because the originals don't look that worn and I plan to de-grime that area. But eyeballing an unmounted belt can be deceiving, I should put the new ones on before worrying about it any more.
Even if new belts give better contact the T-slot block would still seem to be too far outboard, but I hadn't considered the 4000 RPM option that Cal noted. That presumably would have a much larger motor sheave which would require the idler to be shifted outboard (right, to front of lathe) -- hence the design of that T-slot block to accommodate different idler positions.
I bought a left side (rear) idler from boomerang69, finally got around to installing it yesterday. It looks like it belongs there.
With both idlers present the original right hand (front) idler now has much better contact with the belts, now that the new idler is taking a lot of slack out of the belts.
So, mystery solved for my lathe, I think it originally had the left hand idler which wandered away at some point.
I have a '41 Round dial. Mine has been hacked or converted to a different motor, 2 hp. Mine has only one 'V' belt. It does have an idler on the right hand side (looking from the back or motor view of the lathe). It tensions a flat belt, I think for the feed gear box. I am missing the idler on the left hand side. Who ever setup the new motor, didn't leave any slop in the 'V' belt. I would be interest if anyone has the left side idler setup for a round dial.
Tom
I have a '41 Round dial. Mine has been hacked or converted to a different motor, 2 hp. Mine has only one 'V' belt. It does have an idler on the right hand side (looking from the back or motor view of the lathe). It tensions a flat belt, I think for the feed gear box. I am missing the idler on the left hand side. Who ever setup the new motor, didn't leave any slop in the 'V' belt. I would be interest if anyone has the left side idler setup for a round dial.
Tom
I have an extra idler wheel (wheel, bearing, shaft) but no T-slot block, if that would help.
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MG 10EE drive belt idler mystery
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Originally Posted by PaulM
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